Former pharmaceuticals executive Martin Shkreli is poking back at House Oversight and Government Reform Committee ranking member Elijah E. Cummings, D-Md., regarding a committee subpoena to testify on Jan. 26. “Mr. Shkreli was subpoenaed to appear before Congress, and it is his responsibility to take reasonable steps to comply. If he plans on trying to use his own intentional inaction as some kind of bogus excuse for not showing up at Tuesday’s hearing, people will see right through such a juvenile tactic. I hope he reconsiders his current course and avoids any additional legal action against him,” Cummings said in a statement.

Shrekli asked Cummings on Wednesday for his opinion on appearing before the committee after tweeting about receiving the subpoena. Following Cummings’ response, Shrekli tweeted that what he said was “disgusting” and “insulting.”

Your attempt to subvert my constitutional right to the 5th amendment are disgusting & insulting to all Americans @OversightDems@RepCummings